Power transfer system and method

Abstract

A power transfer system includes a positioning-device, a base-coil, and one or more controller-circuits. The positioning-device determines a position of a vehicle moving within a power-transfer-zone. The base-coil is disposed within the power-transfer-zone and emits a magnetic-field in response to electrical power applied to the base-coil. The one or more controller-circuits are in communication with the positioning-device and the base-coil. The positioning-device determines whether any portion of the vehicle overlays the base-coil. The one or more controller-circuits immediately control the electrical power applied to the base-coil such that the base-coil emits the magnetic-field characterized as having value of greater than 27 microteslas, when any portion of the vehicle overlays the base-coil.

We claim: 
     
         1 . A power transfer system, said system comprising:
 a positioning-device, the positioning-device determining a position of a vehicle moving within a power-transfer-zone;   a base-coil disposed within the power-transfer-zone, the base-coil emitting a magnetic-field in response to electrical power applied to the base-coil; and   one or more controller-circuits in communication with the positioning-device, and the base-coil:
 wherein the positioning-device determines whether any portion of the vehicle overlays the base-coil, 
 in accordance with the determination that any portion of the vehicle overlays the base-coil, the one or more controller-circuits immediately control the electrical power applied to the base-coil such that the base-coil emits the magnetic-field characterized as having value of greater than 27 microteslas. 
   
     
     
         2 . The system in accordance with  claim 1 , wherein the system further includes a vehicle-coil installed on the vehicle, the vehicle-coil in communication with the one or more controller-circuits,
 the vehicle-coil generating a sensed-voltage in response to the magnetic-field emitted by the base-coil,   whereby the one or more controller-circuits further control the electrical power applied to the base-coil based on a vehicle-coil-position within the power-transfer-zone when the vehicle overlays the base-coil.   
     
     
         3 . The system in accordance with  claim 2 , wherein the one or more controller-circuits control the electrical power applied to the base-coil such that the vehicle-coil generates the sensed-voltage in a range of 0.5V-0.7V when the vehicle overlays the base-coil. 
     
     
         4 . The system in accordance with  claim 2 , wherein the one or more controller-circuits further control the electrical power applied to the base-coil based on a location of the vehicle-coil on the vehicle when the vehicle overlays the base-coil. 
     
     
         5 . The system in accordance with  claim 1 , wherein the one or more controller-circuits further control the electrical power applied to the base-coil by controlling a voltage across the base-coil. 
     
     
         6 . The system in accordance with  claim 1 , wherein the one or more controller-circuits further control the electrical power applied to the base-coil by controlling a current through the base-coil. 
     
     
         7 . The system in accordance with  claim 1 , wherein the one or more controller-circuits further control a rate of the electrical power applied to the base-coil, the rate characterized by a linear-function. 
     
     
         8 . The system in accordance with  claim 1 , wherein the one or more controller-circuits further control a rate of the electrical power applied to the base-coil, the rate characterized by a polynomial-function. 
     
     
         9 . A method of operating a power transfer system, said method comprising:
 determining a position of a vehicle moving within a power-transfer-zone with a positioning-device;   emitting a magnetic-field, with a base-coil disposed within the power-transfer-zone, in response to electrical power applied to the base-coil;   determining whether any portion of the vehicle overlays the base-coil with the positioning-device; and   controlling the electrical power applied to the base-coil, with one or more controller-circuits in communication with the positioning-device and the base-coil, such that the base-coil immediately emits the magnetic-field characterized as having value of greater than 27 microteslas in accordance with the determination that any portion of the vehicle overlays the base-coil.   
     
     
         10 . The method in accordance with  claim 9 , wherein the system further includes a vehicle-coil installed on the vehicle, the vehicle-coil in communication with the one or more controller-circuits,
 the vehicle-coil generating a sensed-voltage in response to the magnetic-field emitted by the base-coil,   the method further including the step of controlling the electrical power applied to the base-coil, with the one or more controller-circuits, based on a vehicle-coil-position within the power-transfer-zone when the vehicle overlays the base-coil.   
     
     
         11 . The method in accordance with  claim 10 , further including the step of controlling the electrical power applied to the base-coil, with the one or more controller-circuits, such that the vehicle-coil generates the sensed-voltage in a range of 0.5V-0.7V when the vehicle overlays the base-coil. 
     
     
         12 . The method in accordance with  claim 10 , further including the step of controlling the electrical power applied to the base-coil, with the one or more controller-circuits, based on a location of the vehicle-coil on the vehicle when the vehicle overlays the base-coil. 
     
     
         13 . The method in accordance with  claim 9 , further including the step of controlling the electrical power applied to the base-coil, with the one or more controller-circuits, by controlling a voltage across the base-coil. 
     
     
         14 . The method in accordance with  claim 9 , further including the step of controlling the electrical power applied to the base-coil, with the one or more controller-circuits, by controlling a current through the base-coil. 
     
     
         15 . The method in accordance with  claim 9 , further including the step of controlling a rate of the electrical power applied to the base-coil, with the one or more controller-circuits, the rate characterized by a linear-function. 
     
     
         16 . The method in accordance with  claim 9 , further including the step of controlling a rate of the electrical power applied to the base-coil, with the one or more controller-circuits, the rate characterized by a polynomial-function. 
     
     
         17 . A power transfer system, said system comprising:
 a positioning-device;   a base-coil; and   one or more controller-circuits in communication with the positioning-device and the base-coil, wherein when any portion of a vehicle overlays the base-coil, the one or more controller-circuits immediately applies electrical power to the base-coil such that the base-coil emits a magnetic-field characterized as having value of greater than 27 microteslas.